Praying for Rain Sacrifices and the Cult of the Dragon God in Tang China Chung, Soon Mo There was a belief in a connection between the dragons and the downfall of rain in traditional chinese society. The clay dragon had been used to praying for rain activities, and the dragon cult had been worshipped. Dragon temples also increased in Tang-Song transition. This paper examined when the dragon had been authorized as the god and how the dragon temples could have increased. To approach these questions, it should be noted the Five Dragon Altar Sacrifice was institutionalized into Imperial Sacrifices System in Kaiyuan period. Because the dragon could be promoted to be the god and became an object of worship on the basis of this sacrifice. It could inferred that institutionalizing Five Dragon Altar Sacrifice enhanced the authority of emperor Xuanzong. The sacrifice ceremonies held in the very site where he had lived before he became a emperor. This place was thought to be auspicious because it showed the divination that he would be a emperor. After the completion of its ritual procedures and regulations in the year of 728, it was formally institutionalize in Kaiyuanli(開元禮). Taoist ritual elements were added in Tianbao period, and the sacrifice was held constantly. Therefore the dragon was easily able to be the god, dragon god worship also could be spread. We could check the spread of dragon worship through literati``s view of the dragon. Some literati had skeptical awareness and attitudes for the dragon god. But some others had different view of the dragon, they regarded the dragon as the god. The view of the latter became the dominant. The idea that the dragon god has a decisive role in rainfall was rooted in the faith of the people, so literati didn``t need to deny it. With the spread of the dragon cult, many dragon temples were built and gradually increased. Interestingly, geographic distribution of temples was concentrated in the Changjiang basin. We can not overlooked that farmland in this regions had been developed rapidly, and this regions emerged as a 266 中國學報 第六十四輯 financial center for Tang dynasty since Anlushan Rebellion. So the development of this area was closely related to the need and demand for rain praying. Eventually, the dragon temples could be increased. However, dragon cult has its limitation in terms of religious organization. At the same time, Buddhist monks made an their missionary efforts in the Changjiang river basin by combining the Dragon King in Buddhist Sutras with the dragon god. So many dragon god temples were attached to the Buddhist temples, it was a typical of spreading the dragon God cult.